Donald Trump falsely claimed at a rally on Sunday that Hillary Clinton wants to let “650 million people pour in” to the US and “triple the size of our country in one week”.

Speaking in an airplane hangar in Albuquerque, New Mexico, Trump again pushed his hardline immigration stance and warned of the dangers posed by what he described as Clinton’s “open borders” policy.

Trump took his alarmist rhetoric to a new height when boasting about his endorsement from the union which represents ICE and border patrol officers. He told them: “You know, it would be much easier working for Obama or working for crooked Hillary because frankly when you’re working for Hillary, she wants to let people just pour in.”

Trump continued: “You could have 650 million people pour in and we do nothing about it. Think of it, that’s what could happen. You triple the size of our country in one week. Once you lose control of your borders you have no country.”

Trump though has never suggested that Clinton, whom he has long derided as “a globalist”, supported tripling the size of the US through a mass migration unprecedented in world history.

Although Clinton is long on the record in favor of comprehensive immigration reform and a path to citizenship for undocumented immigrants, there is no evidence she favors increasing the US population by 650 million, a total roughly equal to the combined population of Canada, Mexico and the European Union.

Trump’s comments on immigration came hours after he further stoked fears of election fraud in a rally in Colorado.

There, in a state where all voters can vote by mail, he suggested the electoral process was insecure and that his supporters should show up in person at polling places on election day and request a new ballot.

The Republican nominee has long suggested without basis that, as part of “a rigged system”, there is major in-person voter fraud in the US. A recent study found only 31 cases of in-person voter fraud out of a billion ballots cast between 2000-2014.